As a recording media with high speed, big capacity, high reliability and low cost, disk drives are widely used for digital information recording. With the development of information technology in recent years, the recording density of a disk drive has been developed to exceed 100 GB per square inch. The disk drive includes a slider incorporating thin film magnetic elements for recording and reproducing data information stored in the recording media. A surface of the slider facing to the recording media is referred as air bearing surface (ABS).
For example, a slider manufacturing process may be performed as follows: firstly, forming a predetermined deposition film on a wafer; then, cutting off the wafer along a cutting section on which the ABS is exposed, thus forming a row bar on which a plurality sliders arrayed in line; next, mounting the row bar to a holding fixture for lapping, pressing the row bar onto a revolving lapping surface of the holding fixture, and lapping a surface of the row bar to form the ABS; next, offloading the row bar from the holding fixture, collecting a plurality of row bars together according to actual requirement, and machining the ABS to form rails thereon. Here the rails are concave and convex surfaces formed on the ABS and flying over the rotating recording medium in a predetermined height when the slider is in a recording or reproducing operation; then securing the row bar on a cutting fixture and dicing it into individual sliders. At the time, all the slider are separated from each other while still maintaining as an aggregate since all the sliders are still fixed on the cutting fixture; after that, taking all the sliders one by one from the cutting fixture and receiving them in a slider tray.
The above-mentioned process may take various forms of embodiments, however, for slider lapping or rail machining process, the process is implemented based on the aggregate of sliders, and then the slider is separated from each other after completion of the process. It is for sake of working efficiency and product management. As slider is tiny, it is better to perform these processes in a slider-aggregate state prior to slider separating process. According to electric characteristics of each slider measured before they are separated into individual sliders, defective products are sorted out from the separated sliders that are received in the slider tray, and only non-defective products are cleaned and assembled to head gimbal assemblies (HGAs).
Now the process of separating sliders from the cutting fixture is described in further detail. In the past, the above process is performed as follows: heating the slider through a heated plate and then melting an adhesive (refer to Japanese patent publication No. 2001-101635 and Japanese patent publication No. 2001-126225). FIG. 8 is an illustration view of the separating process. FIG. 8(a) shows a plan view of a slider tray which receives separated sliders therein; FIGS. 8(b)-8(c) show cross-sectional views taken along lines b-b and c-c of FIG. 8(a) respectively; FIGS. 8(c)-8(d) show cross-sectional views taken along lines d-d and e-e of FIG. 8(a) respectively. As illustrated in FIG. 8(a), defined in the slider tray 131 are a number of recesses 132 which are arrayed in an interlacing state, and pitch formed between adjacent two of which is of the same distance as that formed between adjacent two sliders. The recess 132 has an aperture 133 defined on bottom surface thereof. The interlaced arrays comprise a first array 134 and a second array 135, and a recess group 136 constructed by these arrays accommodates all sliders of a row bar. Several recess groups 136 may be formed in the slider tray 131, and as will be illustrated in later, several row bars may be handled simultaneously.
As illustrated in FIGS. 8(b)-8(e), the cutting fixture 121 loaded with the sliders 42 faces downwardly, so that the sliders 42 are exposed to the recesses 132 of the first array 134. The slider tray 131 inclines downwards slightly from the first array 134 to the second array 135. By this inclination configuration, when the slider tray 131 is dipped into NMP (N-Methyl-2-Pyrrolidone) solvent, the NMP (N-Methyl-2-Pyrrolidone) solvent will be immersed into the recess 132 through the aperture 133 of the recess 132, and dissolve the adhesive disposed between the slider 42 and the cutting fixture 121, such that the slider 42 is disconnected with the cutting fixture 121. The sliders 42 associated with the first array 134 fall into the recesses 132 thereof directly, and those associated with the second array 135 glide on the slider tray 131 under action of gravity and then fall into the recesses 132 of the second array 135. Consequently, the sliders are separated from the row bar and collected into the recesses 132. Here, the recesses 132 take the interlacement configuration rather than a linear configuration, since the linear configuration results in inter-walls between two recesses thinning and thus sufficient stiffness cannot be guaranteed.
Next, defective and non-defective sliders are sorted out according to electric characteristics of the sliders measured before they are separated. However, as discussed above, as the sliders are very tiny, when being moved to the slider tray 131, the sliders arranged on the row bar may not be received in the slider tray 131 in their original sequence. Especially, with further miniaturization of the slider, the weight of a slider is reduced to be lower than 0.1 g, thus any slight shock or air flow may cause the slider moving, accordingly, the rate of slider disorder may still be increased. If this instance happens, it is needed to read a slider ID code attached on the deposition surface of a slider. The ID code is shown on the deposition surface, and each number takes size of 5×10 μm. However, when the sliders enter into the slider tray 131, the ID code becomes unreadable since the deposition surface is in side surface position. Accordingly, gripping tools, such as tweezers are needed to fetch out the sliders from the slider tray 131 one by one, and then the ID code on the side surface is identified using a microscope.
Reference patent 1: Japanese Patent Application NO. 2001-101635
Reference patent 2: Japanese Patent Application NO. 2001-126225
However, in the prior art, since the pitch arrangement of the recesses of the slider tray depends upon the arrangement pitch of the sliders, so the following problems arise.
Firstly, a new slider tray should be manufactured each time when the pitch of the slider is changed. Namely, as described above, the arrangement pitch between the recesses of the slider tray is designed as the same as that of the sliders of the row bar. Consequently, it is necessary to reduce the slider pitch of the row bar (i.e., improve integration degree of the chip) for purpose of increasing slider yield of each row bar; hence, a new slider tray should be manufactured each time when the pitch of a slider is altered.
Even if the above problems are ignored, the following problems still exist in prior arts. Firstly, suppose that size of slider is constant and only cut gap between sliders is shortened, thus thickness of the partition-walls between the recesses must be reduced. However, it is difficult to manufacture a slider tray with thin partition-walls, because the machining size limit of the thickness of partition-wall is about 100 μm.
In addition, mini-type slider, such as 20% slider (approximate size: 0.7×0.8×0.23 mm) developed in recent years also reduces the recess size with reduction of the slider. However, as described above, as inspection of the sliders is performed by manual, it is very difficult to fetch out the sliders from the size-reduced recesses or put them in the size-reduced recesses. Consequently, in slider inspection process, it is prone to put the defective sliders into other recesses wrongly, and then make the defective sliders enter into later manufacturing process. Furthermore, as a plurality of sliders are moved totally at the same time, there is a possibility to make them all get into a mess state due to a single error, and it is required to re-determine the ID codes of the sliders which ID codes are missed from monitoring.
Additionally, the slider-separating method in the prior art also causes the following problems. Specifically, the cutting fixture contacts with the slider tray when separating the sliders, and pitch x between recess domains is confined by thickness of the cutting fixture (refer to FIG. 7(a)). Thus it is difficult to form recesses in regions located between the recess domains, thus the regions are vacant and slider capacity is limited. In the following conditions, it will become problematic. Namely, when the above process is operated, many particles are stick to the sliders and few particles are stick to the slider trays (though the slider trays are constructed of particle-free material, in fact few particle may still be generated), accordingly, the sliders are required to be cleaned. Since it is prohibited to have tiny particle attached on the ABS of the slider in cleaning process, the sliders are cleaned in a very rigid environment, and a whole cleaning cycle is time-consuming and high costly. Therefore, it is desired to reduce cleaning cycles. As the cleaning process is implemented based on a whole slider tray, it is desired for a slider tray to contain sliders as many as possible. However, the amount of the sliders which can be contained by the slider tray is limited due to reasons described above, accordingly, the cleaning efficiency can not be improved.
In addition, there are still the following problems in prior art: the recesses arrangement is too jammed, the slider tray stiffness is insufficient or the sliders processing is obstructed because the arrangement pitch of the recesses of the slider tray depends upon the arrangement pitch of the sliders. Furthermore, the method of separating the sliders also limits the slider numbers holding on the slider tray.
Moreover, it is also known that the NMP solvent may contaminate the ABS of the slider when the slider is dipped into the solvent for resolving adhesive. Additionally, the ABS of the slider faces the bottom of the recess when in the resolving process, thus the ABS should be turned up after handled by the resolving process. This ABS flipping work leads to low work efficiency. In addition, once all the sliders are placed into the recesses and defective sliders are sorted out and removed from the recesses (especially sorted according to electric characteristic), many recesses of the slider tray will be empty. As this empty state of the recesses result in low cleaning efficiency, it is needed for the empty recesses to be filled with other non-defective sliders. Since it is difficult to perform cleaning process for individual and independent sliders, thus in conventional technology, it is preferable to provide a process for avoiding particle contamination.
Therefore, the invention is aimed to provide a slider manufacturing method and device which are capable of separating a row bar constituting with an array of sliders, into individual sliders efficiently and reliably and then holding these sliders without dependency upon slider size or arranging pitch thereof.